Windows and Mac OS updates every few years. Windows 7 arrives on October 22nd and Apple’s Snow Leopard will show up in September. The Linux kernel, the heart of Linux distributions, however, gets updated every few months.
What this means for you is that Windows and Mac OS are taking large, slow steps, while Linux is constantly evolving. Thus, Linux’s changes may not be as big from version to version, but they tend to be more thoroughly tested and stable. What most users will like in this distribution starts with a faster boot-up for Linux.